JP3933985B2 - Manufacturing method of laminate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a laminate, and more particularly to an improved method for producing a laminate comprising laminating a laminate material on a substrate by heating.
[0002]
[Prior art]
The method of laminating the fluororesin on the base material is to heat the fluororesin film or sheet and press it on one or both sides of the base material, to co-extrude the molten fluororesin with the base material, or based on the fluororesin dispersion. For example, there is a method of impregnating a base material with a fluororesin by applying to the material (by dipping, spraying, etc.). The base material is mainly formed of an inorganic material, and examples thereof include cloth of inorganic fibers such as glass fibers, carbon fibers, and aramid fibers, knits, and wire mesh using metal wires. Organic materials such as aramid fiber cloths and knits having excellent heat resistance can also be used as the base material.
[0003]
However, the fluororesin has a higher specific gravity than other resins and easily generates static electricity, so that it is difficult to handle, and the above laminating methods also have problems.
For example, in the impregnation method, in order to obtain a laminate having a uniform thickness, it is necessary to appropriately select the dispersion viscosity, the fluororesin concentration in the dispersion, the type of surfactant used for dispersion, and the like. Some surfactants have an odor, and it is necessary to take measures against the odor when the impregnated product is dried.
[0004]
In the case of laminating (laminating) a film or sheet on a substrate using a roll, particularly in double-sided lamination, the release property from the roll is the biggest problem. Also, since the melting point of fluororesin is high, it is necessary to use a roll with good heat resistance. However, because of the nature of the heat medium (silicone, naphthalene, etc.) currently used to optimize the temperature distribution of the roll, The heat resistance limit is said to be about 400 ° C., which is insufficient for laminating the fluororesin sufficiently. In addition, when a molten fluororesin film or sheet is laminated to a substrate such as a wire mesh with a roll, the film thickness is reduced on the metal wire, the uniformity of the laminated fluororesin film or sheet is impaired, and the film or The sheet is easily torn. Another problem is that foreign matter on the roll surface adheres to the surface of the laminate. Further, when the roll clearance is not uniform, or when the roll is distorted or bent, the thickness of the laminate becomes non-uniform.
[0005]
In addition, in any of the conventional lamination methods described above, as the size of the laminate increases, the device becomes larger and the cost for installing the device becomes enormous.
[0006]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a novel lamination method that solves the problems found in the above-described impregnation method and lamination method using rolls.
[0007]
[Means for Solving the Problems]
According to the present invention, the above problem is repeatedly laminated material to a substrate, the space between the substrate and the laminate material, with respect to the outer and overlapping substrate laminate material, while maintaining the vacuum, an external Heating is started from a position farthest from the place where the reduced pressure is applied without applying a force from the outside, and the laminated material is heated from the outside toward the place where the reduced pressure is applied, and the laminated material is laminated on the substrate. It is solved by the manufacturing method of the laminated body characterized by this.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
As the laminated material used in the present invention, any material can be used as long as it becomes flexible by heating and can be fused. For example, any polymer material can be used, from a general-purpose resin having a melting point of about 80 ° C. to a fluororesin such as polytetrafluoroethylene (PTFE) having a melting point of 327 ° C. or higher. In particular, fluororesins include PTFE, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-hexafluoropropylene copolymer (FEP), polyfluoride. Any of a transparent fluororesin and a translucent or opaque fluororesin such as vinylidene (PVDF) can be used in the method of the present invention.
[0009]
When it is necessary to color the laminate, a color film may be used as the laminate material. Alternatively, a transparent laminate material may be used, and a color film may be sandwiched between the base material and the laminate material. In this case, since the laminated material is brought into close contact with the base material under reduced pressure, the position of the sandwiched color film is not shifted, so that the pattern can be formed faithfully.
[0010]
When a laminate excellent in abrasion resistance is required, an inorganic filler reinforcing agent such as glass fiber or carbon fiber can be added to the laminate material. In addition, in cases where foreign matter adhesion prevention and antistatic properties are required on the surface of the laminate, a conductive additive such as carbon or graphite may be added to the laminate material.
[0011]
As a base material, the base material mainly used for the laminated body formed from the inorganic material, for example, glass fiber, carbon fiber, inorganic fiber cloth such as aramid fiber, knit, metal wire was used. Wire mesh can be used.
When the substrate is manufactured from a magnetic material, the substrate can be heated by electromagnetic induction, so that the laminate can be used as a planar heating element or a film heater. Alternatively, the substrate can be made of an exothermic material.
[0012]
In the laminating method of the present invention, since the space between the base material and the laminated material is reduced in pressure, when the laminated material is heated and softened, the laminated material is fused to the base material by the reduced pressure. Therefore, in the laminating method of the present invention, it is preferable to laminate the laminating material without applying external force (force other than force generated by decompression). However, in order to promote fusion, pressure may be applied from the outside by means such as a roll.
The degree of depressurization and the heating temperature are determined by the melting point, thickness, number of laminated layers, etc. of the laminated material (film or the like). For example, in the case of laminating two 25 μm-thick films, it is desirable to reduce the degree of decompression or set the heating temperature to a relatively low temperature near the melting point. On the other hand, when two films having a thickness of 1000 μm are laminated, it is desirable to set the heating temperature to a temperature relatively higher than the melting point or to increase the degree of pressure reduction. It is desirable to adjust the heating rate, for example, the flow rate of hot air, depending on the thickness of the film. This is because, when heated to the melting point or higher of the laminated material, the strength is extremely lowered, and if it is a thin laminated material, it may be destroyed.
[0013]
The laminate material may have any shape and size as long as it can apply a reduced pressure, but preferably the laminate material and the substrate are shielded from the outside except where the reduced pressure is applied. It is preferable. For example, two films or sheets of laminated material are overlapped, and the periphery is sealed except for a portion for applying reduced pressure. Or a base material may be arrange | positioned on a planar gas impermeable member, a laminated material may be arrange | positioned so that a base material may be covered, and a laminated material peripheral edge may be sealed to a gas impermeable member. For sealing, the periphery of the film or sheet of the laminated material may be heat-sealed, or an adhesive tape or the like may be attached to the periphery.
[0014]
Heating may be performed in any manner, but preferably, heating is started from a location farthest from the location where the reduced pressure is applied, and the heating location is moved toward the location where the reduced pressure is applied. The moving speed is not particularly limited, but is adjusted so that the laminated material is sufficiently fused to the substrate.
[0015]
The heating means is not particularly limited, but preferably hot air is used as a heat source. Radiant heat from other heating means such as a heater can also be used. In any case, the heating means is preferably used so as not to come into direct contact with the laminated material.
According to the method of the present invention, a laminate having a wide range of thicknesses can be produced. For example, a laminate having an overall thickness of about 25 μm to 20 mm can be produced. With proper heating, thinner or thicker laminates can be produced.
[0016]
The laminate produced by the method of the present invention can be used for various applications. Typical uses are as follows.
1. Building roofing materials, wall materials (eg, membrane construction building materials, garage roofs, etc.), snowmelt roofs, greenhouse materials (roofs, walls, windows, etc.)
2. 2. Rooftop waterproof sheet 3. Indoor / outdoor separation shutter 4. Sound insulation (sound insulation) wall Fences, verandas6. Antenna 7. 7. flue or duct 8. Corrosion resistant tank Railway snow melting equipment (for snow melting of points and signals)
10. 10. Panel heating element, film heater, floor, wall or ceiling heating panel Throw heater 12. Explosion-proof membrane 13. Print substrate 14. Building isolator (or equipment)
15. Automotive hood 16. Antifouling membrane [0017]
【Example】
EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited to these Examples.
[0018]
Example 1
As the laminated material, a 100 μm thick film (400 mm width × 800 mm) of modified PTFE (M112) manufactured by Daikin Industries, Ltd. was used. On the other hand, SUS304 wire mesh (8 mesh; wire diameter of about 0.54 mmφ) (350 mm square) was baked at 300 ° C. and used as a substrate.
[0019]
First, the modified PTFE film is spread on the cleaned table so that there is no wrinkle, and SUS304 wire mesh is placed on half of the modified PTFE film (the length of 400 mm from one end). Was folded to obtain a temporary laminate having a three-layer structure.
Next, the whole circumference of the three-layer structure temporary laminate was hermetically sealed, leaving a vacuum suction hole in a part of the temporary laminate. Subsequently, using a vacuum pump, the internal space of the film was reduced to 760 mmHgG from the vacuum suction hole to remove the air inside the sealed film, thereby forming a three-layered precursor laminate.
[0020]
Next, using two hot air welders heated to 360 ° C., the modified PTFE film was heated by blowing hot air on both sides of the end portion (end portion far from the vacuum suction hole) of the precursor laminate while sucking. At this time, the distance between the surface of the precursor laminate and the tip of the welder nozzle was kept about 5 to 7 mm. The modified PTFE film became transparent by heating. In this state, the nozzle of the hot air welder was moved toward the vacuum suction hole, and the entire precursor laminate was welded. The modified PTFE film was in close contact with the wire mesh. After the welder nozzle passed over the film, the film was cooled to obtain a laminate in which translucent modified PTFE films were laminated on both sides of the wire mesh. Residual bubbles were not observed inside the film.
[0021]
Measurement of peel strength of laminate After the obtained laminate was cut into a width of 10 mm, a 180 ° peel test was performed at an peel rate of 100 mm / min using an autograph manufactured by Shimadzu Corporation. The peel strength was 0.3 to 0.7 kgf / cm. In some cases, the film was broken during peeling.
[0022]
Example 2
As a laminated material, one 100 μm thick film (400 mm width × 800 mm) of PTFE (M12) manufactured by Daikin Industries, Ltd. and one 50 μm thick film (350 mm square) of PFA manufactured by Daikin Industries, Ltd. were used. On the other hand, the same SUS304 wire mesh used in Example 1 was used as a base material.
[0023]
First, spread the modified PTFE film on the cleaned table, place the SUS304 wire mesh on the half of the modified PTFE film, place the PFA film on it, and then fold the other half of the modified PTFE film on the PFA film. It was set as the temporary laminated body of 4 layer structure.
Next, the entire circumference of the four-layer structure temporary laminate was hermetically sealed, leaving a vacuum suction hole in a part of the temporary laminate. Subsequently, using a vacuum pump, the internal space of the film was reduced to 760 mmHgG from the vacuum suction hole to remove the air inside the sealed film, and a four-layer structure was released to form a precursor laminate.
[0024]
Next, in the same manner as in Example 1, the precursor laminate was heated from one end of the precursor laminate toward the vacuum suction hole to obtain a laminate in which a wire mesh and a film were welded. Residual bubbles were not observed inside the film.
[0025]
Measurement of peel strength of laminate The laminate obtained was subjected to a 180 ° peel test in the same procedure as in Example 1. The peel strength was 1.3 to 1.46 kgf / cm.
[0026]
Example 3
As the laminated material, one 250 μm thick film (400 mm width × 800 mm) of modified PTFE (M112) manufactured by Daikin Industries, Ltd. and one 50 μm thick film (350 mm square) of PFA manufactured by Daikin Industries, Ltd. were used. On the other hand, the same SUS wire mesh used in Example 1 was used as a base material.
[0027]
First, the modified PTFE film is spread on a cleaned table, the PFA film is placed on the modified PTFE film half without wrinkles, and a SUS304 wire mesh is further placed thereon, and then the remaining half of the modified PTFE film is further deposited thereon. Was folded to form a temporary laminate having a four-layer structure.
[0028]
Next, the entire circumference of the four-layer structure temporary laminate was hermetically sealed, leaving a portion of the vacuum suction hole in a part of the temporary laminate. Subsequently, using a vacuum pump, the internal space of the film was reduced to 760 mmHgG from the vacuum suction hole to remove the air inside the sealed film, thereby forming a four-layered precursor laminate.
[0029]
Next, in the same manner as in Example 1, the precursor laminate was heated from one end of the precursor laminate toward the vacuum suction hole to obtain a laminate in which a wire mesh and a film were welded. Residual bubbles were not observed inside the film.
[0030]
Measurement of peel strength of laminate The laminate obtained was subjected to a 180 ° peel test in the same procedure as in Example 1. The peel strength was 3.5 to 3.9 kgf / cm.
[0031]
Example 4
As a laminated material, one 100 μm thick film (400 mm width × 800 mm) of modified PTFE (M112) manufactured by Daikin Industries, Ltd. and two 50 μm thick films (350 mm square) of PFA manufactured by Daikin Industries, Ltd. were used. On the other hand, glass cloth (coarse) (350 mm square) was baked at 350 ° C., and the glass cloth was impregnated with silicone, dried and baked, and used as a substrate.
[0032]
Spread the modified PTFE film without wrinkles on the cleaned table, place one sheet of PFA film on the half, then place a 350 mm square glass cloth, and then stack the remaining sheet of PFA film on the glass cloth. . Next, the remaining half of the modified PTFE film was folded to obtain a temporary laminate having a five-layer structure.
Next, the entire circumference of the five-layer structure temporary laminate was hermetically sealed, leaving a vacuum suction hole in a part of the temporary laminate. Subsequently, using a vacuum pump, the internal space of the film was reduced to 760 mmHgG from the suction hole to remove the air inside the sealed film, thereby forming a five-layered precursor laminate.
[0033]
Next, in the same manner as in Example 1, the precursor laminate was heated from one end of the precursor laminate toward the vacuum suction hole to obtain a laminate in which a wire mesh and a film were welded. Residual bubbles were not observed inside the film.
[0034]
Measurement of peel strength of laminate The laminate obtained was subjected to a 180 ° peel test in the same procedure as in Example 1. Peeling occurred at the substrate portion, and the peel strength was 0.6 to 0.8 kgf / cm.
[0035]
Example 5
A laminate of a PFA film AF-0100 (thickness: 100 μm) manufactured by Daikin Industries, Ltd. cut to a width of 400 mm and a length of 80 cm was used. On the other hand, SUS304 wire mesh (8 mesh) (350 mm square) was used as a substrate.
[0036]
A PFA film was spread on a cleaned table, a SUS304 wire mesh was placed on half of the PFA film (40 cm), and the other half of the PFA film was folded back to form a three-layer temporary laminate. Next, the entire circumference of the three-layer structure temporary laminate was hermetically sealed, leaving a vacuum suction hole in a part of the temporary laminate. Subsequently, using a vacuum pump, the internal space of the film was reduced from the vacuum suction hole to 760 mmHgG to form a three-layered precursor laminate.
[0037]
Using a hot air welder (manufactured by Leister, Switzerland), hot air of 360 to 370 ° C. is blown on both sides of the end of the laminate that is farthest from the vacuum suction hole of the precursor laminate, and the film is heated until it is completely transparent While melting and maintaining that state, the hot air welder was moved toward the vacuum suction hole to fuse the entire precursor laminate.
[0038]
When the same peel test as in Example 1 was performed, the peel strength was 0.8 to 1 kg / cm, but the film was mostly broken. That is, the film and the wire mesh were firmly bonded.
[0039]
Example 6
Implemented except that Daikin Industries, Ltd. PFA film AF-0500 (thickness 500 μm) cut to a width of 400 mm and a length of 80 cm was used as the laminated material, and SUS304 wire mesh (30 mesh) (350 mm square) was used as the base material A laminate was produced in the same procedure as in Example 5.
The PFA film that became transparent by heating entered the sucked wire mesh. The film surface had relatively few irregularities and a good laminate was obtained.
A 180 ° C. peel test was performed in the same procedure as in Example 1. The peel strength was 6.3 to 7.5 kgf / cm. Most of the specimens broke.
[0040]
Example 7
As a laminated material, one 0.5 mm thick film (400 mm width × 80 cm) of modified PTFE (M112) manufactured by Daikin Industries, Ltd. and two PFA films AF-0100 (350 mm square) manufactured by Daikin Industries, Ltd. were used. On the other hand, one SUS304 punched metal plate (thickness 0.3 mm; 350 mm square; about 39000 holes with a diameter of 0.5 mmφ) was used as a substrate.
Spread the modified PTFE film on the cleaned table, and stack one PFA film, punched metal plate and the other PFA film in this order on the half of the modified PTFE film, and then fold the other half of the PTFE film back to 5 layers. It was set as the temporary laminated body of the structure.
[0041]
Next, the entire temporary laminate was hermetically sealed leaving a vacuum suction hole in a part of the temporary laminate, and the internal space of the film was reduced from the vacuum suction hole to 760 mmHgG using a vacuum pump. Then, the film edge part on the opposite side of a vacuum suction hole was heated from both surfaces using the hot air heater of 360-380 degreeC. The modified PTFE film became transparent by heating. In addition, the melt viscosity of the film decreased and the resin entered the 0.5φ hole of the punching metal. At the same time, the hot air heater was sequentially moved toward the vacuum suction hole, and the entire temporary laminated body corner was fired to form a laminated body having a punching metal plate as a base material.
[0042]
Resin entered the holes of the punching metal plate, and the front and back films were bonded through the holes to obtain a single laminate having a five-layer structure.
In this case, when the SUS plate is blasted or surface-treated with a primer or the like, the adhesiveness of fluororesin (PTFE, PFA, etc.) to SUS is further improved.
[0043]
Example 8
As the laminated material, one 500 μm thick film (400 mm width × 80 cm) of a modified FEP film (NF-0500) manufactured by Daikin Industries, Ltd. was used. On the other hand, one glass cloth (thickness 0.3 mm) (350 mm square) was used as a substrate.
[0044]
The FEP film was spread on a cleaned table, and a glass cloth was placed on the half of the FEP film, and then the remaining half of the PTFE film was folded back to form a three-layer temporary laminate.
[0045]
Next, the outer periphery of the temporary laminate was hermetically sealed, leaving a vacuum suction hole in a part of the temporary laminate, and the internal space of the film was reduced from the suction hole to 760 mmHgG using a vacuum pump. Then, using a hot air welder, heat both sides of the film end opposite to the vacuum suction hole with hot air of 360 to 380 ° C., and gradually check the FEP film while making the FEP film transparent. It moved toward the suction hole to form a laminate.
The peel strength was 7 to 8 kgf / cm, and the film broke in most of the test pieces.
[0046]
Example 9
One aluminum plate (thickness 1.5 mm; 400 mm square), one glass cloth (350 mm square) heat-treated at 300 ° C. and impregnated with silicone, Daikin Industries PFA film (thickness 50 μm; stretched 5-7%; 340 mm square) One sheet and one 100 μm-thick film (400 mm square) of modified PTFE (M112; stretched 5 to 7%) manufactured by Daikin Industries, Ltd. were prepared.
First, the surface of the aluminum plate is cleaned with acetone, a glass cloth is placed thereon, a PFA film and a PTFE film are stacked thereon to form a four-layer temporary laminate, and a vacuum suction hole is left between the aluminum plate and PTFE. Sealed.
[0047]
Using a vacuum pump, the space in the temporary laminate was reduced to 760 mmHgG from the vacuum suction hole to form a precursor laminate.
Further, while vacuum suction was applied, heating was performed with a hot air welding machine at 370 ° C. from both sides of the end farthest from the vacuum suction hole of the camouflaged laminate, and the heated portion was moved toward the vacuum suction hole to heat-weld the fluororesin film. . Thereafter, the aluminum plate was removed to obtain a laminate in which a PFA film and a PTFE film were laminated on one side of a glass cloth.
In addition, when the unevenness | corrugation of the base material was small at the time of lamination | stacking, it was confirmed that the expansion | swelling which generate | occur | produces at the time of a heating can be absorbed by using a stretched film, and the wrinkle generation rate of a laminated body reduces significantly.
[0048]
【The invention's effect】
According to the laminating method of the present invention, a heating device such as a heating roll can be laminated (laminated) without directly contacting a laminated material such as a fluororesin film or sheet. Further, the laminate is not easily contaminated. It is possible to pressurize the laminate after heating lamination. Since the laminated material does not contact the heating source and the pressure source, there is no problem of mold release.
Since heating can be performed indirectly, a wide and long laminate product can be easily produced. Since pressure is not applied, the thickness variation of the laminate is very small. Since heating is performed above the melting point of the laminated film, delicate temperature control is not necessary.
When the substrate is made of fibers, film breakage of the film does not occur on the fiber portion.
Since no roll is used, wrinkles due to center misalignment do not occur.
Since the base material does not come into contact with other articles before and after the lamination of the laminated material, misalignment of a wire mesh or a glass cloth as the base material does not occur.
Since the layers are laminated while being sucked under reduced pressure, no bubbles remain inside the laminate.

Claims (4)

The laminated material is stacked on the base material, and the pressure between the base material and the laminated material is reduced without applying external force while maintaining the reduced pressure with respect to the outer side of the stacked base material and the laminated material. A method for producing a laminate , wherein heating is started from a place farthest from a place to be applied, the laminate material is heated from the outside toward a place to which the reduced pressure is applied, and the laminate material is laminated on a base material. Periphery of the laminate material overlaid method for manufacturing a laminate according to claim 1, which is sealed except in places where vacuum is applied. The manufacturing method of the laminated body of Claim 1 or 2 in which a laminated material consists of a fluororesin. The manufacturing method of the laminated body in any one of Claims 1-3 which heats at the temperature more than melting | fusing point of a laminated material.